Centrifugal extractor



Oct. 30, 1928.

Inventor ClfmarlesA. Keley. by

His Attorn ey.

Patented Oct. 30, 1928.

UNITED STATES PATENT OFFICE.

CHARLES A. KELSEY, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELC-TRIC COMPANY, A CORPORATION OF NEW YORK.

CENTRIFUGAL EXTRACTOR.

Application filed December 10, 1927.

My invention relates generally to centrifugal extractors and moreparticularly to an improved construction for continuously feedingmaterial therethrough.

In centrifugal extractors as heretofore constructed it has been thepractice to provide a rotatable perforated receptacle into which liquorcontaining solid material in suspension was delivered, the liquid beingthrown outwardly through the perforations in the receptacle bycentrifugal force and the solid material being retained on the innerwall of the receptacle. It was necessary to stop the rotation of theseextractors periodically and remove the solid material from the walls ofthe receptacles which was inconvenient and which decreased the capacityof the extract-ors over any given period of use.

It has been proposed t0 continuously feed material through extractors ofthis type by various means so that it would be unnecessary to interrupttheir operation to remove solid material therefrom, but sucharrangements as heretofore proposed have been objectionable because ofthe excessive amount of power required to operate theextractors when thefeeding devices were used; The increase of power required in using thesefeeding devices has been due largely to the fact that solid materialbecame packed between the feeding elements and the wall of t-hereceptacle. Moreover, in many forms of these devices the power appliedto them has been such as to produce a torque directly opposing` themeans employed for rotating the eX- tractor which further increased thepower required.

The object of my invention is to provide an arrangement for `feedingmaterial through the perforated receptacle of a centrifugal. extractorof this type such that the power required to operate the feedingmechanism will he minimized, and such that the feeding means will notincrease the load on the means for driving the extractor. I accomplishthis by providing means for feeding the material through the perforatedreceptacle, which moves in one direction along a wall of the receptacleand which then moves in another direction along and away from the wallof the receptacle. Such `an arrangement feeds the material along thewall of the receptacle during movement of the feeding means in onedirection without caus- Serial No. 239,100.

ing thematerial to become packed between the feeding means and thereceptacle, and 'permits the feeding means, during its movement in theother direction, to slide freely over the solid material. In this wayforce is applied for feeding the material only in the direction of feedwithout producing any substantial torque resisting the means foi'driving the extractor and without accumulating packed solid materialbetween the receptacle and the feeding element.

My invention will be more fully set forth in the following descriptionreferring-to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specication.

ln the drawing Fig. l is a vertical, sectional view of a centrifugal.extractor embodying my invention; Fig. 2 is a transverse sectional viewon the line Q-Q of Fig. l, and Fig. 3 in a fragmentary section of theextractor, in which the position of the feeding element during itsdownward movement is indicated in full lines, and in which its posit-ionduring its upward movement is indicated in dotted lines.

Referring to the drawing, I have shown my invention, for convenience inillustration, in connection with a centrifugal eX- tractor'comprising arotatable cylindrical receptacle l0 having a perforated side wall l0awithin which the solid material is retained and through which the liquidis discharged, the openings in the perforated side wall being madesmall. enough to retain the solid material therein. The perforated walll0, which is reenforced bya plurality of bands l0b so as to withstandcentrifugal stresses, is mounted on a base member 10C of the receptacleprovided with outlets l0d through which solid material separated fromthe liquor fed into the receptacle is discharged. The receptacle isdriven by an electric motor ll or other suitable means mounted on anoverhanging framework l2, and the receptacle is suspended from thisframework by a shaft 18 which is driven by the motor. The shaft 13entends through an opening 100 inthe upper wall of the receptacle and issecured to the base l()C of the receptacle so as to form a driving`connection between the motor ll and the receptacle. Liquid dischargedfrom the receptacle 10 impinges against the wall of a cylindricalchamber 1d arranged about the receptacle and flows into an annularliquid receiving trough 15 formed in the bottom thereof from which itflows through a ipe 16. A wall 15a of the trough extends a out the base10c of the receptacle in spaced relation thereto so as to permit thebase member to turn freely in the chamber lll. The wall 15a extendsabove the openings 10 in the base 10c and is inclined toward theopenings 101 so that the solid material discharged from the receptacleis directed by the wall into the hopper 17 arranged below the liquidreceiving trough.

When liquor containing solid material, such as crystals or pulp, is fedinto the rotat ing receptacle 10, it is desirable that the liquid shouldpass through the perforated side wall of thereceptacle 10 and that thesolid material should gradually move toward the bottom of the receptacleand be discharged through the openings 10d into the hopper 17. However,it is apparent that unless some arrangement is provided for feeding thepulp or crystals toward the bottom oft-he receptacle that it will beretained on the side Walls of the receptacle by centrifugal force. Inaccordance with my invention the flow of the material along the wall ofthe receptacle 10 is controlled by providing a feeding element arrangedadjacent the inner wall of the receptacle and moving this element in onedirection along the axis of rotation of the receptacle so as to feed thematerial toward the bottom of the receptacle, and then moving thefeeding element toward the top of the receptacle and away from tho sidewall thereof, so that the material. moved downwardly during the firstmentioned movement will not be disturbed by the element in returningtoits initial position. In the construction illustrated in the drawing, aplurality of suoli feeding elements 19 are arranged between a hollowreciprocating cylindrical member 2O of somewhat smaller diameter thanthe inside of the receptacle 10 and the perforated side wall of thereceptacle. The feeding elements are arcuate in form and pivotallyconnected at 19a to the reciprocating cylindrical member 2O so that uponrotation of the member the feeding elements are thrown outwardly to asubstantially horizontal position by centrifugal force. The feedingelements are formed so that when they are in this horizontal. positionthey overlap, as indicated at 19", and extend closely adjacent thewallsA over the inner surface of the solid material against which theyare urged by centrifugal force. ln this way the feeding elements aremoved upwardly to their initial position without disturbing the solidmaterial which has been fed along the inner wall of the receptacleduring downward movement of the feeding elements in a horizontalposition against the stops 20u. Although I have shown the feedingelement-s arranged in series of annular groups in which the feedingelements overlap they may be arranged in any other convenient manner.The cylindrical member 2O is supported during its reciprocatorymovement, which actuates the feed` ing elements as above described, by alower bearing 2Ob and an upper bearing 20c which is carried by atransverse imperforate partition wall 20d formed in the cylindricalmember in spaced relation to the upper wall thereof, the lower bearing2()d being slidably keyed at 13a to the shaft 13 so that the receptacleand the cylindrical member are rotated together by the motor 11. lt isnot essential, however, to rotate the cylindrical member 2O with thereceptacle 10 and in some instances it may be desired to dispense withthe lrey 13a and rotate or oscillate the cylindrical member relative tothe receptacle by other suitable mechanism. The cylindrical member 20may be reciprocated in any suitable manner, but in the constructionshown it is reciprocated by a gear and crank mechanism including a lever21, which is pivotallysupported at -22 on a bracket 23 carried by theframework 12, and which is driven by a worm 24 secured to the shaft 13connecting the motor 11 with the receptacle 10. rllhe movement of thelever 21 is transmitted to the cylindrical member 2O so as toreciprocate the same by a roller 25 secured to the lever 21, which isarranged between flanges 26 formed on the hollow shaft 27 extendingthrough the open ing 2Oe in the upper wall of the member 2O and securedto the imperforate partition wall 2()d formed in the cylindrical memberadjacent the upper wall thereof. A supply pipe 18, which is supported inany convenient manner, is arranged to discharge liquor having solidmaterial in suspension through the opening 2Oe in the upper wall of thecylindrical member 20 into the space between the upper wall of thecylindrical member and the imperforate partition 20d, from which itflows through openings 2()f into the space between the two uppermost ofthe feeding members 19, the cylindrical member 20 and the perforatedwall 10a of the receptacle. As the openings 20f are formed in the sidewall of the cylindrical member' 2O at the upper surface of theimperforate partition 20d and between the two uppermost feeding elements19, the solid material and liquor will not be trapped within thecylindrical member 20 and the solid material will not accumulate in thetop of the receptacle 10.

In the operation of the centrifugal extractor which I have described,liquid having solid material in suspension is fed into the cylindricalmember 20 and is discharged through the openings 20f into the spacebetween the cylindrical member and the per forated wall of thereceptacle 10. The re ceptacleand the cylindrical member are rotated athigh speed by the electric motor 11 so t-hat the liquid is dischargedthrough the perforations 1()a into the chamber 14 from which it isremoved through the pipe 16, and the solid material is retained againstthe inner wall of the receptacle 10 by centrifugal force. Thecylindrical member 2O is rotated with the receptacle 10 by the key 13aand is reciprocated longitudinally of the receptacle at the same time bythe roller 25, which is actuated by the Worm 24 driving the link 21through the gear and crank mechanism supported on the bracket 23. As thecylindrical member 20 is moved downwardly the feeding elements 19 areretained in their horizontal positionagainst the stops 2Oa so that thefeeding elements move along the inner wall of the receptacle 10 and feedthe solid material, which accumulates therein, downwardly, Upon upwardmovement of the cylindrical member 20 the feeding elements 19 are swungabout their pivotal supports 19a away from the perforated side wall 10aof the receptacle 10, as indicated in dotted lines in Fig. 3, by thesolid material indicated at M which is retained against the perforatedwall 10a of the receptacle by centrifugal force. Although centrifugalforce retains the feeding elements against the material on theperforated side wall of the receptacle 10, it does not exert sufficientforce to disturb the material during the upward movement of the feedingelements. As the feeding elements are retained against the solidmaterial on the inner wall of the receptacle by centrifugal force-duringthis upward move-L ment of the member 20, upon its downward movementwhich follows the friction of the feeding elements against the materialturns them about their pivotal supports 19a to a horizontal positioninto engagement with the stops 20a and feeds the solid materialdownwardly, as previously described.

The centrifugal extractor which I have disclosed is merely illustrativeof one embodiment of my invention, and I intend, therefore, in theappended-claims to cover all modifications which do not depart from thespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is 1. A centrifugal extractor comprising a receptacle having aperforated side wall, means for rotating said receptacle, a feedingelement adjacent the side wall of said receptacle, means for supportingsaid element, and means for moving said support so that said elementmoves back and forth along the side wall of said receptacle, saidsupporting means being arranged so that said element moves away fromsaid side wall when said supporting means is moved in one direction.

2. A centrifugal extractor comprising a receptacle having a perforatedside wall, a member in said receptacle, means for rotatingl saidreceptacle, means for reciprocating said member along the axis ofrotation of said receptacle, and means pivotally supported on saidmember responsive to reciprocatory movement of said member for feedingmaterial through said receptacle.

3. A centrifugal extractor comprising a receptacle having a perforatedside wall, means for rotating said receptacle, a member in saidreceptacle, a feeding element pivotally connected to said member andadapted to be brought closely adjacent the side wall of said receptacleupon rotation of said member, means for reciprocating said member, andmeans for retaining said element closely adjacent the side wall of saidreceptacle during its movement in one directionv only so as to feedmaterial through said receptacle and to permit said element to swingaway from the side wall of said receptacle during movement of saidmember in the other direction.

4. A centrifugal extractor comprising a receptacle having a perforatedside wall, means for rotating said receptacle, and means for feedingmaterial through said receptacle comprising a member in said receptaclehaving a plurality of elementspivotally connected thereto which areadapted to be moved closely adjacent and away from the side wall of saidreceptacle during rotation of said member, said elements being shaped soas to form a continuous annular wall when they are "adjacent the sidewall of said receptacle.

5. A centrifugal extractor comprising a receptacle having a perforatedside wall, a memberin said receptacle, means for rotating saidreceptacle and said member, means for reciprocating said memberlongitudinally of the axis of rotation of .said receptacle,

and a plurality of feeding elements pivetally connected to said member`which are adapted to be moved closely adjacent the side well of saidreceptacle in response to rotation of the latter, said elements beingshaped so as to overlap and form e continuous annuler Wall when they areclosely adjacent seid side Wall, and means for retaining said elementsclosely adjacent the side Wall of said receptacle during movement ofsaid member in one direction only so es to feed material through saidreceptacle and to permit said elements to swing' away Yfrom the sideWall of said receptacle during movement of said member in the otherdirection. Y

In Witness whereof, I have hereunto set my band this 8th day ofDecember, 192?.

CHARLES A. KELSEY.

